Solid-state battery package

ABSTRACT

A solid-state battery package that includes: a substrate; and a solid-state battery on the substrate. The solid-state battery has: a battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte; and an end-face electrode on an end face of the battery element and connected to one of the positive or negative electrode layers. The substrate has a substrate electrode layer on a main surface thereof, and at least a first side surface of the substrate electrode layer and a first end face of the end-face electrode are substantially on an identical line in a sectional view, a distance between the first side surface and a second side surface of the substrate electrode layer is equal to or more than a minimum distance between the first end face and an end surface of the positive or negative electrode layer that the end-face electrode is not connected.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International applicationNo. PCT/JP2022/018944, filed Apr. 26, 2022, which claims priority toJapanese Patent Application No. 2021-074350, filed Apr. 26, 2021, theentire contents of each of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a solid-state battery package. Morespecifically, the present invention relates to a solid-state batterypackaged so as to be adapted for mounting on a board.

BACKGROUND ART

Hitherto, secondary batteries that can be repeatedly charged anddischarged have been used for various purposes. For example, secondarybatteries are used as power sources of electronic devices such assmartphones and notebooks.

In secondary batteries, a liquid electrolyte is generally used as amedium for ion transfer contributing to charging and discharging. Thatis, a so-called electrolytic solution is used for the secondary battery.However, in such a secondary battery, safety is generally required fromthe viewpoint of preventing leakage of an electrolytic solution. Sincean organic solvent or the like used for the electrolytic solution is aflammable substance, safety is required also in that respect.

Therefore, solid-state batteries using a solid electrolyte instead of anelectrolytic solution have been studied.

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2015-220107-   Patent Document 2: Japanese Patent Application Laid-Open No.    2007-5279

SUMMARY OF THE INVENTION

It is conceivable that a solid-state battery is used by being mounted ona printed wiring board and the like together with other electroniccomponents, and in that case, a structure suitable for mounting isrequired. For example, a package in which a solid-state battery isdisposed on a substrate has the substrate electrically connect with theoutside and thereby is adapted for mounting.

The solid-state battery has: a battery element having a positiveelectrode layer, a negative electrode layer, and a solid electrolyteinterposed between electrode layers of the positive electrode layer andthe negative electrode layer; and an end-face electrode provided on thebattery element. In addition, in the solid-state battery, the electrodelayers (positive electrode layer/negative electrode layer) may expandand contract during charging and discharging. The inventors of thepresent application have noticed that there is still a problem to beovercome in previously proposed solid-state batteries, and have found aneed to take measures therefor.

Specifically, the battery element expands and contracts due to expansionand contraction of the electrode layer. On the other hand, the end-faceelectrode itself provided on the battery element is less likely toexpand and contract. Due to the difference in the degree of expansionand contraction, stress may act from the solid-state battery side to thesubstrate side. In particular, this stress may increase from the centralregion side of the battery element toward the interface region sidebetween the electrode layer and the end-face electrode. That is, amongthe stresses acting from the solid-state battery side to the substrateside, the stress along the interface region between the electrode layerand the end-face electrode becomes relatively the largest. Therefore,the largest stress acts on a predetermined portion of the main surfaceof the substrate located below the end-face electrode, and thereby thesubstrate may be cleaved. As a result, the cleaved substrate may causeinfiltration of moisture from the external environment, and may causedeterioration of battery characteristics.

The present invention has been devised in view of such problems. Thatis, a main object of the present invention is to provide a solid-statebattery package capable of suitably suppressing substrate cleavage.

To achieve the above object, an aspect of the present inventionprovides: a solid-state battery package including a substrate and asolid-state battery on the substrate. The solid-state battery has: abattery element having a positive electrode layer, a negative electrodelayer, and a solid electrolyte interposed between the positive electrodelayer and the negative electrode layer; and an end-face electrode on anend face of the battery element and connected to one of the positiveelectrode layer or the negative electrode layer. The substrate has, on amain surface thereof on a side opposite to the solid-state battery, asubstrate electrode layer, and at least a first side surface of thesubstrate electrode layer and a first end face of the end-face electrodeare substantially on an identical line in a sectional view of thesolid-state battery package, a distance between the first side surfaceand a second side surface of the substrate electrode layer opposite tothe first side surface is equal to or more than a minimum distancebetween the first end face of the end-face electrode and an end surfaceof the one of the positive electrode layer or the negative electrodelayer that the end-face electrode is not connected.

The solid-state battery package according to one aspect of the presentinvention is capable of suitably suppressing substrate cleavage.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a sectional view schematically illustrating the internalconfiguration of a solid-state battery.

FIG. 2 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to one aspect of the presentinvention.

FIG. 3 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 4 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 5 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 6 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 7 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 8 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 9 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 10 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 11 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention.

FIG. 12 is a sectional view schematically illustrating a solid-statebattery package, and is a schematic view particularly illustrating acertain substrate configuration example.

FIG. 13A is a step sectional view schematically illustrating a processfor manufacturing a solid-state battery package according to an aspectof the present invention.

FIG. 13B is a step sectional view schematically illustrating a processfor manufacturing a solid-state battery package according to an aspectof the present invention.

FIG. 13C is a step sectional view schematically illustrating a processfor manufacturing a solid-state battery package according to an aspectof the present invention.

FIG. 13D is a step sectional view schematically illustrating a processfor manufacturing a solid-state battery package according to an aspectof the present invention.

FIG. 13E is a step sectional view schematically illustrating a processfor manufacturing a solid-state battery package according to an aspectof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a solid-state battery package according to the presentinvention will be described in detail. Although the description will bemade with reference to the drawings as necessary, the illustratedcontents are only schematically and exemplarily illustrated for theunderstanding of the present invention, and the appearance, thedimensional ratio, or the like may be different from the actual ones.

The term “solid-state battery package” as used herein refers, in a broadsense, to a solid-state battery device (or a solid-state batteryarticle) configured to protect the solid-state battery from the externalenvironment, and in a narrow sense, to a solid-state battery articlethat includes a substrate adapted for mounting and protects thesolid-state battery from the external environment.

The term “sectional view” as used herein is based on a form viewed froma direction substantially perpendicular to the stacking direction in thestacked structure of the solid-state battery (briefly, a form in thecase of being cut along a plane parallel to the layer thicknessdirection). In addition, the term “plan view” or “plan view shape” usedin the present specification is based on a sketch drawing when an objectis viewed from an upper side or a lower side along the layer thicknessdirection (that is, the above stacking direction).

The terms “up-down direction” and “left-right direction” directly orindirectly used in the present specification respectively correspond tothe up-down direction and the left-right direction in the drawings.Unless otherwise specified, the same reference signs or symbols denotethe same members and sites, or the same semantic contents. In onepreferred aspect, it can be considered that a vertical downwarddirection (that is, a direction in which gravity acts) corresponds to a“downward direction”/“bottom side” and the opposite directioncorresponds to an “upward direction”/“top side”.

The term “solid-state battery” used in the present invention refers to,in a broad sense, a battery whose constituent elements are composed ofsolid and refers to, in a narrow sense, all solid-state battery whoseconstituent elements (particularly preferably all constituent elements)are composed of solid. In a preferred aspect, the solid-state battery inthe present invention is a stacked solid-state battery configured suchthat layers constituting a battery constituent unit are stacked on eachother, and such layers are preferably composed of fired bodies. The term“solid-state battery” encompasses not only a so-called “secondarybattery” that can be repeatedly charged and discharged but also a“primary battery” that can only be discharged. According to a preferredaspect of the present invention, the “solid-state battery” is asecondary battery. The term “secondary battery” is not to be consideredexcessively restricted by its name, which can encompass, for example, apower storage device and the like. In the present invention, thesolid-state battery included in the package can also be referred to as a“solid-state battery element”.

Hereinafter, the basic configuration of the solid-state batteryaccording to the present invention will be first described. Theconfiguration of the solid-state battery described here is merely anexample for understanding the invention, and not considered limiting theinvention.

[Basic Configuration of Solid-State Battery]

The solid-state battery includes: at least electrode layers: a positiveelectrode and a negative electrode; and a solid electrolyte.Specifically, as illustrated in FIG. 1 , a solid-state battery 100includes a solid-state battery stacked body including a batteryconstituting unit composed of a positive electrode layer 110, a negativeelectrode layer 120, and a solid electrolyte 130 at least interposedbetween the electrode layers.

For the solid-state battery, each layer constituting the solid-statebattery may be formed by firing, and the positive electrode layer, thenegative electrode layer, the solid electrolyte, and the like may formfired layers. Preferably, the positive electrode layer, the negativeelectrode layer, and the solid electrolyte are each fired integrallywith each other, and thus, the solid-state battery stacked bodypreferably forms an integrally fired body.

The positive electrode layer 110 is an electrode layer containing atleast a positive electrode active material. The positive electrode layermay further contain a solid electrolyte. In a preferred aspect, thepositive electrode layer is composed of a fired body including at leastpositive electrode active material particles and solid electrolyteparticles. In contrast, the negative electrode layer is an electrodelayer containing at least a negative electrode active material. Thenegative electrode layer may further contain a solid electrolyte. In apreferred aspect, the negative electrode layer is composed of a sinteredbody containing at least negative electrode active material particlesand solid electrolyte particles.

The positive electrode active material and the negative electrode activematerial are substances involved in the transfer of electrons in thesolid-state battery. Ions move (or conduct) between the positiveelectrode layer and the negative electrode layer through the solidelectrolyte to accept and donate electrons, whereby charging anddischarging are performed. Each electrode layer of the positiveelectrode layer and the negative electrode layer is preferably a layercapable of occluding and releasing lithium ions or sodium ions, inparticular. More particularly, the solid-state battery is preferably anall-solid-state secondary battery in which lithium ions or sodium ionsmove between the positive electrode layer and the negative electrodelayer through the solid electrolyte interposed, thereby charging anddischarging the battery.

(Positive Electrode Active Material)

Examples of the positive electrode active material included in thepositive electrode layer 110 include at least one selected from thegroup consisting of lithium-containing phosphate compounds that have aNASICON-type structure, lithium-containing phosphate compounds that havean olivine-type structure, lithium-containing layered oxides,lithium-containing oxides that have a spinel-type structure, and thelike. Examples of the lithium-containing phosphate compounds that have aNASICON-type structure include Li₃V₂(PO₄)₃. Examples of thelithium-containing phosphate compounds that have an olivine-typestructure include Li₃Fe₂(PO₄)₃, LiFePO₄, and/or LiMnPO₄. Examples of thelithium-containing layered oxides include LiCoO₂ and/orLiCo_(1/3)Ni_(1/3)Mn_(1/3)O₂. Examples of the lithium-containing oxidesthat have a spinel-type structure include LiMn₂O₄ and/orLiNi_(0.5)Mn_(1.5)O₄. The types of the lithium compounds are notparticularly limited, and may be regarded as, for example, alithium-transition metal composite oxide and a lithium-transition metalphosphate compound. The lithium-transition metal composite oxide is ageneric term for oxides containing lithium and one or two or moretransition metal elements as constituent elements, and the lithiumtransition metal phosphate compound is a generic term for phosphatecompounds containing lithium and one or two or more transition metalelements as constituent elements. The types of transition metal elementsare not particularly limited and are, for example, cobalt (Co), nickel(Ni), manganese (Mn), iron (Fe), and the like.

In addition, examples of positive electrode active materials capable ofoccluding and releasing sodium ions include at least one selected fromthe group consisting of sodium-containing phosphate compounds that havea NASICON-type structure, sodium-containing phosphate compounds thathave an olivine-type structure, sodium-containing layered oxides,sodium-containing oxides that have a spinel-type structure, and thelike. For example, in the case of the sodium-containing phosphatecompounds, examples thereof include at least one selected from the groupconsisting of Na₃V₂(PO₄)₃, NaCoFe₂ (PO₄)₃, Na₂Ni₂Fe (PO₄)₃, Na₃Fe₂(PO₄)₃, Na₂FeP₂O₇, Na₄Fe₃(PO₄)₂(P₂O₇), and NaFeO₂ as a sodium-containinglayered oxide.

In addition, the positive electrode active material may be, for example,an oxide, a disulfide, a chalcogenide, a conductive polymer, or thelike. The oxide may be, for example, a titanium oxide, a vanadium oxide,a manganese dioxide, or the like. The disulfide is, for example, atitanium disulfide, a molybdenum sulfide, or the like. The chalcogenidemay be, for example, a niobium selenide or the like. The conductivepolymer may be, for example, a disulfide, a polypyrrole, a polyaniline,a polythiophene, a poly-para-styrene, a polyacetylene, a polyacene, orthe like.

(Negative Electrode Active Material)

Examples of the negative electrode active material included in thenegative electrode layer 120 include at least one selected from thegroup consisting of oxides containing at least one element selected fromthe group consisting of titanium (Ti), silicon (Si), tin (Sn), chromium(Cr), iron (Fe), niobium (Nb), and molybdenum (Mo), carbon materialssuch as graphite, graphite-lithium compounds, lithium alloys,lithium-containing phosphate compounds that have a NASICON-typestructure, lithium-containing phosphate compounds that have anolivine-type structure, and lithium-containing oxides that have aspinel-type structure. Examples of the lithium alloys include Li—Al.Examples of the lithium-containing phosphate compounds that have aNASICON-type structure include Li₃V₂(PO₄)₃ and/or LiTi₂(PO₄)₃. Examplesof the lithium-containing phosphate compounds that have an olivine-typestructure include Li₃Fe₂(PO₄)₃ and/or LiCuPO₄. Examples of thelithium-containing oxides that have a spinel-type structure includeLi₄Ti₅O₁₂.

In addition, examples of negative electrode active materials capable ofoccluding and releasing sodium ions include at least one selected fromthe group consisting of sodium-containing phosphate compounds that havea NASICON-type structure, sodium-containing phosphate compounds thathave an olivine-type structure, and sodium-containing oxides that have aspinel-type structure.

Further, in the solid-state battery, the positive electrode layer andthe negative electrode layer are made of the same material.

The positive electrode layer and/or the negative electrode layer mayinclude a conductive material. Examples of the conductive materialincluded in the positive electrode layer and the negative electrodelayer include at least one of metal materials such as silver, palladium,gold, platinum, aluminum, copper, and nickel, and carbon.

Further, the positive electrode layer and/or the negative electrodelayer may include a sintering aid. Examples of the sintering aid includeat least one selected from the group consisting of a lithium oxide, asodium oxide, a potassium oxide, a boron oxide, a silicon oxide, abismuth oxide, and a phosphorus oxide.

The thicknesses of the positive electrode layer and negative electrodelayer are not particularly limited, but may be, independently of eachother, for example, 2 μm to 50 μm, particularly 5 μm to 30 μm.

(Positive Electrode Current Collecting Layer/Negative Electrode CurrentCollecting Layer)

Although not an essential element for the electrode layer, the positiveelectrode layer 110 and the negative electrode layer 120 mayrespectively include a positive electrode current collecting layer and anegative electrode current collecting layer. The positive electrodecurrent collecting layer and the negative electrode current collectinglayer may each have the form of a foil. The positive electrode currentcollecting layer and the negative electrode current collecting layer mayeach have, however, the form of a fired body, if more importance isplaced on viewpoints such as improving the electron conductivity,reducing the manufacturing cost of the solid-state battery, and/orreducing the internal resistance of the solid-state battery by integralfiring. As the positive electrode current collector constituting thepositive electrode current collecting layer and the negative electrodecurrent collector constituting the negative electrode current collectinglayer, it is preferable to use a material with a high conductivity, andfor example, silver, palladium, gold, platinum, aluminum, copper, and/ornickel may be used. The positive electrode current collector and thenegative electrode current collector may each have an electricalconnection for being electrically connected to the outside, and may beconfigured to be electrically connectable to an end-face electrode. Itis to be noted that when the positive electrode current collecting layerand the negative electrode current collecting layer have the form of afired body, the layers may be composed of a fired body including aconductive material and a sintering aid. The conductive materialincluded in the positive electrode current collecting layer and thenegative electrode current collecting layer may be selected from, forexample, the same materials as the conductive materials that can beincluded in the positive electrode layer and the negative electrodelayer. The sintering aid included in the positive electrode currentcollecting layer and the negative electrode current collecting layer maybe selected from, for example, the same materials as the sintering aidsthat can be included in the positive electrode layer/the negativeelectrode layer. As described above, in the solid-state battery, thepositive electrode current collecting layer and the negative electrodecurrent collecting layer are not essential, and a solid-state batteryprovided without such a positive electrode current collecting layer or anegative electrode current collecting layer is also conceivable. Moreparticularly, the solid-state battery included in the package includedthe present invention may be a solid-state battery without any currentcollecting layer.

(Solid Electrolyte)

The solid electrolyte is a material capable of conducting lithium ionsor sodium ions. In particular, the solid electrolyte 130 that forms thebattery constituent unit in the solid-state battery may form a layercapable of conducting lithium ions between the positive electrode layer110 and the negative electrode layer 120. It is to be noted that thesolid electrolyte has only to be provided at least between the positiveelectrode layer and the negative electrode layer. More particularly, thesolid electrolyte may be present around the positive electrode layerand/or the negative electrode layer so as to protrude from between thepositive electrode layer and the negative electrode layer. Specificexamples of the solid electrolyte include any one, or two or more of acrystalline solid electrolyte, a glass-based solid electrolyte, and aglass ceramic-based solid electrolyte.

Examples of the crystalline solid electrolyte include oxide-basedcrystal materials and sulfide-based crystal materials. Examples of theoxide-based crystal materials include lithium-containing phosphatecompounds that have a NASICON structure, oxides that have a perovskitestructure, oxides that have a garnet-type or garnet-type similarstructure, and oxide glass ceramic-based lithium ion conductors.Examples of the lithium-containing phosphate compound that has a NASICONstructure include Li_(x)M_(y)(PO₄)₃ (1≤x≤2, 1≤y≤2, M is at least oneselected from the group consisting of titanium (Ti), germanium (Ge),aluminum (Al), gallium (Ga), and zirconium (Zr)). Examples of thelithium-containing phosphate compounds that have a NASICON structureinclude Li_(1.2)Al_(0.2)Ti_(1.8)(PO₄)₃. Examples of the oxides that havea perovskite structure include La_(0.55)Li_(0.35)TiO₃. Examples of theoxides that have a garnet-type or garnet-type similar structure includeLi₇La₃Zr₂O₁₂. In addition, examples of the sulfide-based crystalmaterials include thio-LISICON, for example,Li_(3.25)Ge_(0.25)P_(0.75)S₄ and Li₁₀GeP₂Si₂. The crystalline solidelectrolyte may contain a polymer material (for example, a polyethyleneoxide (PEO)).

Examples of the glass-based solid electrolyte include oxide-based glassmaterials and sulfide-based glass materials. Examples of the oxide-basedglass materials include 50Li₄SiO₄-50Li₃BO₃. In addition, examples of thesulfide-based glass materials include 30Li₂S-26B₂S₃-44LiI,63Li₂S-36SiS₂-1Li₃PO₄, 57Li₂S-38SiS₂-5Li₄SiO₄, 70Li₂S-30P₂S₅, and50Li₂S-5OGeS₂.

Examples of the glass ceramic-based solid electrolyte includeoxide-based glass ceramic materials and sulfide-based glass ceramicmaterials. As the oxide-based glass ceramic materials, for example, aphosphate compound (LATP) containing lithium, aluminum, and titanium asconstituent elements, and a phosphate compound (LAGP) containinglithium, aluminum, and germanium as constituent elements can be used.LATP is, for example, Li_(1.07)Al_(0.69)Ti_(1.46) (PO₄) 3. LAGP is, forexample, Li_(1.5)Al_(0.5)Ge_(1.5) (PO₄). In addition, examples of thesulfide-based glass ceramic materials include Li₇P₃S₁₁ andLi_(3.25)P_(0.95)S₄.

In addition, examples of the solid electrolyte capable of conductingsodium ions include sodium-containing phosphate compounds that have aNASICON structure, oxides that have a perovskite structure, and oxidesthat have a garnet-type or garnet-type similar structure. Examples ofthe sodium-containing phosphate compound having a nasicon structureinclude Na_(x)M_(y)(PO₄)₃ (1≤x≤2, 1≤y≤2, M is at least one selected fromthe group consisting of Ti, Ge, Al, Ga and Zr).

The solid electrolyte may include a sintering aid. The sintering aidincluded in the solid electrolyte may be selected from, for example, thesame materials as the sintering aids, which can be included in thepositive electrode layer/the negative electrode layer.

The thickness of the solid electrolyte is not particularly limited. Thethickness of the solid electrolyte layer located between the positiveelectrode layer and the negative electrode layer may be, for example, 1μm to 15 μm, particularly 1 μm to 5 μm.

(End-face Electrode)

The solid-state battery is typically provided with end-face electrodes140. In particular, an end-face electrode is provided on a side surfaceof the solid-state battery. More specifically, the side surfaces areprovided with a positive-electrode-side end-face electrode 140Aconnected to the positive electrode layer 110 and anegative-electrode-side end-face electrode 140B connected to thenegative electrode layer 120 (see FIG. 1 ). Such end-face electrodespreferably contain a material having high conductivity. The specificmaterials of the end-face electrodes are to be considered notparticularly limited, but examples thereof include at least one selectedfrom the group consisting of silver, gold, platinum, aluminum, copper,tin, and nickel.

[Feature of Solid-State Battery Package According to Present Invention]

According to the present invention, the solid-state battery is packaged.More particularly, the solid-state battery package includes a substrateadapted for mounting, and has a configuration in which the solid-statebattery is protected from the external environment.

FIG. 2 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to one aspect of the presentinvention. As illustrated in FIG. 2 , a solid-state battery package 1000according to an aspect of the present invention includes a substrate 200so that a solid-state battery 100 is supported. Specifically, thesolid-state battery package 1000 includes the substrate 200 adapted formounting and the solid-state battery 100 provided on the substrate 200and protected from the external environment.

The inventors of the present application have intensively studied asolution for suitably suppressing cleavage of the substrate 200 in thesolid-state battery package 1000, and as a result, have devised thepresent invention having the following technical idea.

Specifically, the present invention has a technical idea that at theportion to be readily acted by the stress from the solid-state battery100 side to the substrate 200 side that may occur at the time ofcharging and discharging the solid-state battery 100, which has beenfound by the inventors of the present application, a member that makesthe stress less likely to act on the substrate 200 is purposelyprovided.

To achieve the technical idea mentioned above, the present invention hasthe following technical feature (see FIG. 2 ). Specifically, thesubstrate 200 has a configuration that the substrate 200 has, on onemain surface 230 on a side opposite to the solid-state battery 100, atleast one of: a positive-electrode-side substrate electrode layer 210A;and a negative-electrode-side substrate electrode layer 210B disposed tobe separately opposed to the positive-electrode-side substrate electrodelayer 210A, each of which is capable of electrical connection with thesolid-state battery 100.

On the other hand, the substrate 200 includes, on another main surface240, a substrate electrode layer 220 with which the solid-state batterypackage 1000 is mounted to an external board, specifically, apositive-electrode-side substrate electrode layer 220A and anegative-electrode-side substrate electrode layer 220B disposed to beseparately opposed to the positive-electrode-side substrate electrodelayer 220A. The substrate electrode layer 210 on the solid-state batteryinstallation side and the substrate electrode layer 220 on the mountingside are configured to be electrically connectable via a metal memberprovided inside the substrate 200. The metal member may be made of, forexample, at least one metal material selected from the group consistingof copper, aluminum, stainless steel, nickel, silver, gold, tin, and thelike.

For enabling electrical connection between the solid-state battery 100and the substrate electrode layers 210 of the substrate 200, theend-face electrodes 140 of the solid-state battery 100 and the substrateelectrode layer 210 of the substrate 200 can be connected with a bondingmember 600 interposed therebetween. The bonding member 600 plays a partin at least electrical connection between the end-face electrodes 140 ofthe solid-state battery 100 and the substrate 200, and may include, forexample, a conductive adhesive. As an example, the bonding member 600may be made of an epoxy-based conductive adhesive containing a metalfiller such as Ag.

When the positive-electrode-side substrate electrode layer 210A and thenegative-electrode-side substrate electrode layer 210B are notparticularly distinguished, reference sign 210 is used for the substrateelectrode layers. When the positive electrode layer 110 and the negativeelectrode layer 120 are not particularly distinguished from each other,reference sign 115 is used as the reference sign of the electrodelayers. When the positive-electrode-side end-face electrode 140A and theend-face electrode 140B of the negative electrode layer are notparticularly distinguished, reference sign 140 is used as the referencesign of the end-face electrodes.

On the premise of the above configuration, as illustrated in FIG. 2 ,with respect to a case where at least one side surface 211 of thesubstrate electrode layer 210 and an end face 141 of the end-faceelectrode 140 are substantially on an identical line, a distance Libetween the one side surface 211 and another side surface 212 of thesubstrate electrode layer 210 is equal to or more than a minimumdistance L2 between the end face 141 of the end-face electrode 140 onthe same electrode side and a side surface 115 a of the solid-statebattery electrode layer 115 on an opposite electrode side that isseparately opposed to the end face 141. The term “solid-state batteryelectrode layer” as used herein refers to an electrode layer that is acomponent of the solid-state battery, and may also be referred to as anelectrode layer on the solid-state battery side. The term “substrateelectrode layer” as used herein refers to an electrode layer that is acomponent of the substrate, and may also be referred to as an electrodelayer on the substrate side. Specifically, the term “substrate electrodelayer” particularly refers to an electrode layer disposed on the mainsurface on a side opposite to the solid-state battery (which may also bereferred to as an upper main surface), which is on the reverse side ofthe main surface on which an external board is mounted, of the two mainsurfaces of the substrate opposite to each other. The phrase “one sidesurface of the substrate electrode layer and an end face of the end-faceelectrode are substantially on an identical line” refers to a positionalrelationship in which the end face of the end-face electrode and the oneside surface of the substrate electrode layer are substantially inseries with each other via a bonding member or directly. The one sidesurface of the substrate electrode layer referred to herein includes notonly an actual one side surface of the substrate electrode layer butalso an apparent one side surface that can be arranged in series withthe end face of the end-face electrode. Each of the end face of theend-face electrode and the one side surface of the substrate electrodelayer may be linear or curved.

As found by the inventor of the present application, among the stressesacting from the solid-state battery 100 side to the substrate 200 side,the stress along the interface region 180 between the solid-statebattery electrode layer 115 and the end-face electrode 140 is relativelythe largest, so that the stress can act on the predetermined portionside of the substrate 200 located below the end-face electrode 140. In abroad sense, the term “interface region” used in the presentspecification refers to a region including a boundary portion where thesolid-state battery electrode layer 115 and the end-face electrode 140are in contact with each other and a vicinity portion of the boundaryportion. The term “interface region” as used herein refers in a narrowsense to a portion of 0% or more and less than 5% of the width of theregion between the interface region and the central region of thebattery element with respect to the interface region.

In this regard, according to the above technical feature, in a sectionalview, a distance Li between the one side surface 211 and the anotherside surface 212 of the substrate electrode layer 210 (corresponding tothe width dimension of the substrate electrode layer 210) is equal to ormore than a minimum distance L2 between the end face 141 of the end-faceelectrode 140 on the same electrode side and the side surface 115 a ofthe solid-state battery electrode layer 115 on the opposite electrodeside. In other words, in a sectional view, the another side surface 212of the substrate electrode layer 210 and the side surface 115 a of thesolid-state battery electrode layer 115 on the opposite electrode sidecan be located on substantially an identical line. The term “minimumdistance” as used herein refers to a distance at which a straight linehorizontal distance connecting a predetermined portion of the end faceof the end-face electrode and a predetermined portion of the sidesurface of the solid-state battery electrode layer on an oppositeelectrode side, which is separately opposed thereto, is minimized.

As a result, in a sectional view, the another side surface 212 of thesubstrate electrode layer 210 is positioned more inward from aninterface region 180 of the solid-state battery electrode layer 115 onthe same electrode side and the end-face electrode 140. Therefore, thelargest stress that can act on the substrate 200 side along theinterface region 180 between the solid-state battery electrode layer 115on the same electrode side and the end-face electrode 140 is received bythe substrate electrode layer 210 not with a “Point” but with a“Surface”. That is, the substrate electrode layer 210 can function as a“stress-receiving layer”, specifically, a ““planar” stress-receivinglayer”.

Further, the substrate electrode layer 210 itself can be electricallyconnected to the solid-state battery 100, and therefore can be formed ofa metal layer having relatively high strength. The metal layer may bemade of, for example, copper (Cu) plated with gold (Au) (Cu—Au) orcopper (Cu) plated with nickel (Ni) and gold (Au) (Cu—Ni—Au). Althoughnot particularly limited, the thickness of the substrate electrode layer210 can be 2 to 50 μm, for example, 30 μm.

From the above, the largest stress that can act on the substrate 200side along the interface region 180 between the solid-state batteryelectrode layer 115 on the same electrode side and the end-faceelectrode 140 can be received by the “Surface” substrate electrode layer210 having relatively high strength. Due to the stress reception by thesubstrate electrode layer 210, it is possible to suppress the stressfrom acting on a predetermined portion of the main surface 230 of thesubstrate 200 along the interface region 180 between the solid-statebattery electrode layer 115 and the end-face electrode 140. As a result,according to an aspect of the present invention, it is possible tosuitably suppress cleavage of the substrate 200. By suppressing thecleavage of the substrate, it is possible to suppress moistureinfiltration from the external environment to the solid-state battery100 through the substrate 200. Therefore, according to an aspect of thepresent invention, battery characteristics can be improved.

In the above description, according to the main characteristic part ofthe present invention, contents related to cleavage suppression of thesubstrate 200 by stress reception of the substrate electrode layer 210have been described. In addition, the solid-state battery package 1000according to an aspect of the present invention may also have a propertyof preventing water vapor transmission as follows. Therefore, thecontents related to the water vapor transmission prevention will bedescribed below. It is to be noted that the term “water vapor” as usedin the present specification is not particularly limited to water in agaseous state, and also encompasses water in a liquid state and thelike. That is, the term “water vapor” is used to broadly include mattersrelated to water regardless of the physical state. Accordingly, the term“water vapor” can also be referred to as moisture or the like, and inparticular, the water in the liquid state can also encompass dewcondensation water obtained by condensation of water in a gaseous state.

As described above, the substrate 200 supports the solid-state battery100. Therefore, the substrate 200 is provided so as to block the mainsurface of the solid-state battery 100 from the external environment.The presence of the substrate 200 can also suppress the infiltration ofwater vapor into the solid-state battery 100.

As illustrated in FIG. 2 , the substrate 200 has, for example, a mainsurface larger than the solid-state battery. Further, the substrate 200may be a resin substrate. Alternatively, the substrate 200 may be aceramic substrate. In short, the substrate 200 may fall in the categorysuch as a printed wiring board, a flexible substrate, an LTCC substrate,and an HTCC substrate. When the substrate 200 is a resin substrate, thesubstrate 200 may be a substrate composed to include a resin as a basematerial, for example, a substrate that has a stacked structureincluding therein a resin layer. The resin material of such a resinlayer may be any thermoplastic resin and/or any thermosetting resin. Inaddition, the resin layer may be formed by impregnating a glass fibercloth with a resin material such as an epoxy resin, for example.

The substrate preferably serves as a member for an external terminal ofthe packaged solid-state battery. More particularly, the substrate canbe also considered as a terminal substrate for an external terminal ofthe solid-state battery. The solid-state battery package including sucha substrate allows the solid-state battery to be mounted on anotherexternal board (That is, a secondary substrate) such as a printed wiringboard, with the substrate interposed therebetween. For example, thesolid-state battery can be surface-mounted via a support substratethrough solder reflow and the like. For the reasons described above, thesolid-state battery package according to the present invention ispreferably a surface-mount-device (SMD) type battery package.

Furthermore, according to an aspect of the present invention, not onlythe substrate 200 but also the solid-state battery package 1000 itselfcan be configured to prevent water vapor permeation as a whole. Forexample, the solid-state battery package 1000 according to an aspect ofthe present invention can be covered with a covering material 150 suchthat the whole of the solid-state battery 100 provided on the substrate200 is surrounded. Specifically, it may be packaged so that a mainsurface 100A and a side surface 100B of the solid-state battery 100 onthe substrate 200 is surrounded by the covering material 150. In such aconfiguration, all surfaces forming the solid-state battery 100 are notexposed to the outside, and water vapor transmission can be moresuitably prevented.

For example, as shown in FIG. 2 , the covering material 150 may becomposed of a covering insulating layer and a covering inorganic layer,and may have a form in which at least the solid-state battery 100 iscovered with a covering insulating layer 160 and a covering inorganiclayer 170 as the covering material 150.

The covering insulating layer 160 is a layer provided so as to cover themain surface 100A and the side surface 100B of the solid-state battery100. The covering insulating layer 160 largely wraps the solid-statebattery 100 on the substrate 200 as a whole. The material of thecovering insulating layer may be any type as long as it exhibits theinsulating properties. For example, the covering insulating layer 160may include a resin, and the resin may be either a thermosetting resinor a thermoplastic resin. The covering insulating layer 160 may includean inorganic filler. By way of example only, the covering insulatinglayer 160 may be made of an epoxy-based resin containing an inorganicfiller such as SiC.

The covering inorganic layer 170 is provided so as to cover the coveringinsulating layer 160. As shown in FIG. 2 , the covering inorganic layer170 is positioned on the covering insulating layer 160, and thus has aform of largely enclosing the solid-state battery 100 on the substrate200 as a whole together with the covering insulating layer 160. Thecovering inorganic layer may have, for example, a film form.Furthermore, the covering inorganic layer 170 may have the form of alsocovering a side surface 250 of the substrate 200. The coveringinsulating layer 160 forms a suitable water vapor barrier together withthe covering inorganic layer 170, and the covering inorganic layer 170forms a suitable water vapor barrier together with the coveringinsulating layer 160. The material of the covering inorganic layer 170is not particularly limited, and may be metal, glass, oxide ceramics, amixture thereof, or the like. The covering inorganic layer 170 maycorrespond to an inorganic layer that has the form of a thin film, whichis preferably, for example, a metal film. Although it is merely oneexample, the covering inorganic layer 170 may be formed of a platedCu-based and/or Ni-based material having a thickness of 2 μm to 50 μm.

Hereinafter, preferred aspects of the present invention will bedescribed.

In a preferred aspect, in a sectional view, the another side surface 212of the substrate electrode layer 210 is positioned more inward from theside surface 115 a of the solid-state battery electrode layer 115 on theopposite electrode side (see FIG. 3 ).

FIG. 3 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As described above, the basic aspect of the presentinvention shown in FIG. 2 is based on the case where the another sidesurface 212 of the substrate electrode layer 210 and the side surface115 a of the solid-state battery electrode layer 115 on the oppositeelectrode side can be located on substantially the identical line in asectional view. On the other hand, the aspect shown in FIG. 3 ischaracterized in that the another side surface 212 of the substrateelectrode layer 210 is positioned more inward from the side surface 115a of the solid-state battery electrode layer 115 on the oppositeelectrode side, as compared with the aspect illustrated in FIG. 2 .

As found by the inventor of the present application, the stress actingfrom the solid-state battery 100 side to the substrate 200 side mayincrease toward the interface region 180 side between the electrodelayer 115 and the end-face electrode 140. From this, the stress alongthe interface region 180 is the largest, and the stress can graduallydecrease from the interface region 180 toward the central region of abattery element 100X. The term “battery element” as used herein refersto one including the positive electrode layer 110, the negativeelectrode layer 120, and the solid electrolyte 130, excluding theend-face electrode.

Based on this point, the another side surface 212 of the substrateelectrode layer 210 is positioned more inward from the side surface 115a of the solid-state battery electrode layer 115 on the oppositeelectrode side. That is, the substrate electrode layer 210 is extendedto a position that enables opposition to the solid-state batteryelectrode layer 115 on the opposite electrode side in a sectional view.As a result, as compared with the basic aspect shown in FIG. 2 , it ispossible to expand the region of the substrate electrode layer 210 thatcan function as a planar stress-receiving layer.

As a result, among the stresses that can act on the substrate 200 side,the stress along the region between the interface region 180 and thecentral region 100X1 of the battery element 100X can also be received bythe “Surface” substrate electrode layer 210 having relatively highstrength. As a result, it is also possible to suppress the stress alongthe region between the interface region 180 and the central region 100X1of the battery element 100X from acting on a predetermined portion ofthe main surface 230 of the substrate 200.

As an example, the distance Li (corresponding to a width dimension)between the one side surface 211 and the another side surface 212 of thesubstrate electrode layer 210 is preferably 1.5 times or more of theminimum distance L2 in a sectional view (see FIG. 4 ).

FIG. 4 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As described above, the stress that can act on thesubstrate 200 side has a property that the stress can gradually decreasefrom the interface region 180 toward the central region of the batteryelement 100X. Therefore, in the region between the interface region 180and the central region 100X1 of the battery element 100X, the stressalong the region close to the interface region 180 is also relativelyslightly smaller than the stress along the interface region 180.Therefore, stress along this range also adversely affects the substrate200 side. As used herein, the “region close to the interface region”refers to a portion larger than 5% of and equal to or smaller than 20%of the width of the region between the interface region 180 and thecentral region 100X1 of the battery element 100X with respect to theinterface region 180.

Based on this point, the width dimension of the substrate electrodelayer 210 is set to 1.5 times or more of the above-described minimumdistance L2. As a result, as compared with the basic aspect of thepresent invention shown in FIG. 2 , it is possible to expand the regionof the substrate electrode layer 210 that can function as a planarstress-receiving layer. As a result, the stress along the region closeto the interface region 180 can also be suitably received by the“Surface” substrate electrode layer 210 having a relatively highstrength.

From the same point of view, the distance Li (corresponding to a widthdimension) between the one side surface 211 and the another side surface212 of the substrate electrode layer 210 is preferably equal to or morethan a maximum distance L3 between the end face 141 of the end-faceelectrode 140 on the same electrode side and the side surface 115 a ofthe solid-state battery electrode layer 115 on the opposite electrodeside that is separately opposed to the end face 141 (see FIG. 5 ).

FIG. 5 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As found by the inventor of the present application,the stress acting on the substrate 200 side has a property that thestress gradually increases toward the interface region 180 side betweenthe electrode layer 115 and the end-face electrode 140. Based on thispoint, it is preferable that the width dimension of the substrateelectrode layer 210 is secured as compared with the case of the basicaspect illustrated in FIG. 2 in order to be able to receive therelatively large stress along the interface region 180 and the regionclose thereto. Specifically, the width dimension of the substrateelectrode layer 210 is preferably equal to or more than the maximumdistance L3. As a result, as compared with the basic aspect shown inFIG. 2 , it is possible to expand the region of the substrate electrodelayer 210 that can function as a planar stress-receiving layer.

As an example, the distance Li (corresponding to a width dimension)between the one side surface 211 and the another side surface 212 of thesubstrate electrode layer 210 is preferably 2.0 times or more of theminimum distance L2 in a sectional view (see FIG. 6 ).

FIG. 6 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As described above, the stress that can act on thesubstrate 200 side has a property that the stress can gradually decreasefrom the interface region 180 toward the central region of the batteryelement 100X. Therefore, the stress along the region larger than 20% ofand equal to or smaller than 50% of the width of the region between theinterface region 180 and the central region 100X1 of the battery element100X with respect to the interface region 180 is merely relativelyslightly smaller than the stress along the region close to the interfaceregion 180. Therefore, stress along this range also adversely affectsthe substrate 200 side.

Based on this point, the width dimension of the substrate electrodelayer 210 is set to 2.0 times or more of the above-described minimumdistance L2. As a result, as compared with the aspect shown in FIG. 4 ,it is possible to further expand the region of the substrate electrodelayer 210 that can function as a planar stress-receiving layer. As aresult, the stress along the region equal to or smaller than 50% of thewidth of the region between the interface region 180 and the centralregion 100X1 of the battery element 100X can also be suitably receivedby the “Surface” substrate electrode layer 210 having relatively highstrength.

As an example, it is more preferable that the substrate electrode layer210 extends along the main surface 230 of the substrate 200 on the sideopposed to the solid-state battery 100 to such an extent that it doesnot come into contact with the substrate electrode layer 210 on thecounter electrode side (see FIG. 7 ).

FIG. 7 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As found by the inventor of the present application,the stress acting on the substrate 200 side has a property that thestress gradually increases from the central region 100X1 of the batteryelement 100X toward the interface region 180 side between the electrodelayer 115 and the end-face electrode 140. In this regard, although thereis a difference in the magnitude of the stress, the stress can act fromthe solid-state battery 100 side to the substrate 200 side along thewhole region from the interface region 180 to the central region 100X1side of the battery element 100X. For this reason, as illustrated inFIG. 7 , it is more preferable that the substrate electrode layer 210extends along the main surface 230 of the substrate 200 to such anextent that it does not come into contact with the substrate electrodelayer 210 on the counter electrode side.

As a result, the substrate electrode layer 210 can receive the stressthat can act on the substrate 200 side along the whole region from theinterface region 180 to the central region 100X1 side of the batteryelement 100X.

In particular, when both the positive-electrode-side substrate electrodelayer 210A and the negative-electrode-side substrate electrode layer210B adopt the above configuration, the total width of both thesubstrate electrode layers 210A and 210B can be made close to the totalwidth of the solid-state battery 100 in a sectional view. Therefore,both the substrate electrode layers 210A and 210B can receive almost allstress that can act on the substrate 200. As a result, cleavage of thesubstrate 200 can be more suitably suppressed.

In a preferred aspect, the one side surface 211 of the substrateelectrode layer 210 is positioned more outward from the end face 141 ofthe end-face electrode 140 and positioned more inward from an end 231 ofthe main surface 230 of the substrate 200 in a sectional view (see FIG.8 ).

FIG. 8 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. According to the configuration of the present aspect,the substrate electrode layer 210 can be located not only inside butalso outside with respect to the end face 141 of the end-face electrode140. Specifically, the substrate electrode layer 210 can extend outwardfrom the end face 141 of the end-face electrode 140 along the mainsurface 230 of substrate 200 by the distance L4 between its one sidesurface 211 and the end face 141 of the end-face electrode 140.

In this case, the inner portion 210 a of the substrate electrode layer210 positioned on the inner side with respect to the end face 141 of theend-face electrode 140 functions as a planar stress-receiving layer asdescribed above. On the other hand, since the substrate electrode layer210 itself is a metal layer, the outer portion 210 (of the substrateelectrode layer 210 positioned on the outer side with respect to the endface 141 of the end-face electrode 140 may be a portion that isrelatively difficult for water vapor to transmit. This makes it possibleto prevent water vapor infiltrating the solid-state battery 100 sidefrom the external environment via the substrate 200.

As described above, the covering inorganic layer 170 also covers theside surface 250 of the substrate 200, and can be, for example, a metalfilm. Therefore, from the viewpoint of ensuring the electricalinsulation between the substrate electrode layer 210 and the coveringinorganic layer 170 without being in contact with each other, it ispreferable that the one side surface 211 of the substrate electrodelayer 210 is positioned more inward from the side surface of thesubstrate 200, that is, positioned more inward from the end 231 of themain surface 230 of the substrate 200.

In a preferred aspect, the substrate 200 further has, on the mainsurface 230 of the substrate 200 on the side opposite to the solid-statebattery 100, a dummy substrate electrode layer 210C that is disposed tobe separately opposed to the substrate electrode layer 210 and is notelectrically connected to the solid-state battery 100 (see FIG. 9 ).

FIG. 9 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. According to the configuration of the present aspect,the one main surface 230 of the substrate 200 has thereon at least: thesubstrate electrode layer 210 that can function as a planarstress-receiving layer; and the dummy substrate electrode layer 210Cdisposed separately therefrom. On the other hand, at least the substrateelectrode layers 220 on the mounting side are provided on the anothermain surface 240 of the substrate 200 at a predetermined interval. Inthis regard, the presence of the dummy substrate electrode layer 210Chas the following advantages as compared with the case where no one ispresent. Specifically, the arrangement patterns of the electrode layersarranged on the two opposing main surfaces 230 and 240 of the substrate200 can be made similar. Therefore, warpage of the substrate 200 can besuppressed, and as a result, rigidity of the substrate 200 itself can beenhanced. In addition, the dummy substrate electrode layer 210C itselfis a metal layer and may be a portion that is relatively difficult forwater vapor to transmit. This makes it possible to prevent water vaporinfiltrating the solid-state battery 100 side from the externalenvironment via the substrate 200.

As illustrated in FIG. 10 , the dummy substrate electrode layer 210C canbe further disposed between the positive-electrode-side substrateelectrode layer 210A and the negative-electrode-side substrate electrodelayer 210B at an interval not to be in contact with both layers.According to such an arrangement, it is possible to further improve therigidity and the water vapor barrier property of the substrate 200itself. Furthermore, the dummy substrate electrode layer 210C in thiscase is located inside with respect to the end face 141 of the end-faceelectrode 140, and therefore can also function as a planarstress-receiving layer.

In a preferred aspect, a water vapor barrier layer 300 is preferablyprovided between the substrate 200 and the solid-state battery 100 (seeFIG. 11 ).

FIG. 11 is a sectional view schematically illustrating the configurationof a packaged solid-state battery according to another aspect of thepresent invention. As described above, the solid-state battery package1000 includes the substrate 200 and the solid-state battery 100 providedon the substrate 200. The substrate 200 is provided so as to block themain surface of solid-state battery 100 from the external environment.Therefore, it is usually considered that water vapor infiltration intothe solid-state battery can be prevented by the presence of thesubstrate. In this regard, the substrate 200 alone may not sufficientlyprevent water vapor transmission. This is because the substrate 200 canhave permeability to water vapor in the external environment due to thematerial and/or configuration of the substrate 200.

For this reason, it is preferable to provide a water vapor barrier layer300 between the solid-state battery 100 and the substrate 200. The watervapor barrier layer may have, for example, a film form. By disposing thewater vapor barrier layer 300, it is possible to effectively suppresswater vapor transmission to the solid-state battery 100 side through thesubstrate 200. This makes it possible to suppress a decrease in ionicconductivity of the solid electrolyte 130 due to, for example, areaction between water vapor (moisture) infiltrating from the substrate200 and the solid electrolyte 130.

The water vapor barrier layer 300 may be provided so as to be in contactwith the covering insulating layer 160. That is, the covering insulatinglayer 160 is preferably provided so as to cover not only the sidesurface of the solid-state battery 100 but also the lower surface of thesolid-state battery, and the water vapor barrier layer 300 may beprovided so as to be in contact with such a covering insulating layer160. This means that the water vapor barrier layer is provided betweenthe sealing resin surrounding the periphery of the solid-state batteryand the substrate. When the resist layer 400 is provided on thesubstrate 200, the water vapor barrier layer 300 may be disposed betweenthe covering insulating layer 160 and the resist layer 400.

The thickness of each layer of the water vapor barrier layer, thesolid-state battery, and the substrate may be based on an electronmicroscopic image. For example, the thickness of the water vapor barrierlayer and the thickness of the layers constituting the substrate and thesolid-state battery may be based on an image obtained by cutting out thecross section with an ion milling apparatus (model number IM 4000 PLUS;manufactured by Hitachi High-Tech Corporation) and using a scanningelectron microscope (SEM) (model number SU-8040; manufactured by HitachiHigh-Tech Corporation). That is, the thickness dimension in the presentspecification may refer to a value calculated from a dimension measuredfrom an image acquired by such a method.

The term “barrier” as used herein means having such a property ofblocking water vapor transmission that water vapor in the externalenvironment does not pass through the substrate to cause undesirablecharacteristic deterioration for the solid-state battery, and in anarrow sense, means that the water vapor transmission rate is less than5×10⁻³ g/(m²·Day). In short, the water vapor barrier layer preferablyhas a water vapor transmission rate of 0 g/(m²·Day) or more and lessthan 5×10⁻³ g/(m²·Day) (for example, 0.5×10⁻³ g/(m²·Day) or more andless than 5×10⁻³ g/(m²·Day)). Note that the term “water vaportransmission rate” mentioned herein refers to a transmission rateobtained by the MA method under measurement conditions of 85° C. and 85%RH using a gas transmission rate measuring device of model WG-15Smanufactured by MORESCO Corporation.

In a preferred aspect, the water vapor barrier layer 300 is disposed soas to extend along the extending direction of the main surface 230 ofthe substrate 200 (see FIG. 11 ).

According to the arrangement of the water vapor barrier layer 300, asshown in FIG. 11 , the water vapor barrier layer 300 may extend in thewidth direction of the solid-state battery package 1000, and may extendacross the solid-state battery package 1000. This means that the watervapor barrier layer 300 extends in a direction orthogonal to thestacking direction of the solid-state battery. The water vapor barrierlayer 300 extending widely in the direction of the main surface 230 ofthe substrate 300 as described above can more suitably prevent watervapor infiltrating from the external environment via the substrate 200.That is, the water vapor barrier layer 300 can more suitably act so thatwater vapor from the outside of the package does not finally reach thesolid-state battery 100, and as a result, a suitable solid-state batterypackage 1000 in which deterioration of solid-state batterycharacteristics is suppressed in the long term is provided.

The water vapor barrier layer 300 extending in the direction along themain surface direction of the substrate 200 as described above ispreferably provided widely to the region outside the solid-state battery100. That is, it is preferable that the water vapor barrier layer 300 isprovided over a wide range so as to protrude from the solid-statebattery 100. For example, the water vapor barrier layer 300 may extendto the covering material that covers the solid-state battery 100.

For example, the water vapor barrier layer 300 may extend to the outersurface of the covering insulating layer 160 that covers the solid-statebattery 100 on the substrate 200. That is, when the solid-state batterypackage 1000 has the covering insulating layer 160 provided on thesubstrate 200 so as to cover at least the main surface 100A and the sidesurface 100B of the solid-state battery 100, the water vapor barrierlayer 300 preferably extends to the outer surface 160A of the coveringinsulating layer 160 that covers the side surface 100B of thesolid-state battery (see FIG. 11 ). This makes it possible to moresuitably prevent water vapor infiltrating from the external environmentvia the substrate 200. That is, the water vapor barrier layer 300 canmore reliably act so that the external water vapor infiltrating throughthe substrate 200 does not reach the solid-state battery 100.

In a preferred aspect, the water vapor barrier layer 300 is aninsulating layer having electrical insulation properties. That is, thewater vapor barrier layer 300 may be a film including a material havinga high electrical insulation property. This is because a disadvantageousphenomenon such as short circuit can be more easily suppressed. That is,it is possible to prevent the water vapor transmission and also suppressan electrically disadvantageous influence thereof and the like. Such awater vapor barrier layer 300 is not particularly limited as long as itis a material exhibiting insulating properties. Specific examples of thematerial include inorganic insulators such as glass and alumina, organicinsulators such as resins, and the like. These may be used alone, or maybe used in combination of two or more thereof.

As an example, as illustrated in FIG. 11 , the water vapor barrier layer300 may have a single-layer form. Alternatively, the water vapor barrierlayer 300 may have a form including a plurality of layers (that is, amultilayer form described below). There is no particular limitation onthem as long as desired water vapor transmission prevention propertiesare provided.

In a preferred embodiment, the water vapor barrier layer 300 is aninsulating multilayer film. The water vapor barrier property of thewater vapor barrier layer 300 can be improved by multilayering. In suchan insulating multilayer film, the same film may be formed a pluralityof times, or different films may be formed. In the case of differentfilms, an organic insulating barrier layer may be formed on theinorganic insulating barrier layer.

In a preferred aspect, the water vapor barrier layer 300 is provided soas to substantially largely occupy the plan view area of the solid-statebattery package 1000. Specifically, the water vapor barrier layer 300may be provided large so as to occupy the whole region except for theconnection region between the end-face electrode 140 and the substrateelectrode layer 210 of the solid-state battery 100. As described above,the water vapor barrier layer 300 having a large area in plan view canmore reliably prevent water vapor infiltrating from the externalenvironment through the substrate 200.

The water vapor barrier layer is preferably a layer containing silicon.This is because the layer tends to be suitable in terms of electricalinsulation. The water vapor barrier layer containing silicon may be alayer composed of a molecular structure containing not only siliconatoms but also nitrogen atoms and oxygen atoms. This is because thelayer tends to be suitable in terms of electrical insulation andthinning. For example, the water vapor barrier layer has both an Si—Obond and an Si—N bond. That is, both the Si—O bond and the Si—N bond maybe present in the molecular structure constituting the material of thewater vapor barrier layer. When the molecular structure of the layer hasboth an Si—O bond and an Si—N bond, the layer tends to be a thin layerbut a dense layer, and tends to be a water vapor barrier layer that canexhibit more water vapor transmission prevention characteristics.

The water vapor barrier layer containing silicon and the water vaporbarrier layer having both an Si—O bond and an Si—N bond are not based onsiloxane. That is, the water vapor barrier layer according to thepresent invention has a molecular structure containing silicon and anSi—O bond but not containing a siloxane skeleton.

As used herein, the term “Si—O bond” and “Si—N bond” refer to those thatcan be confirmed, for example, based on Fourier transform infraredspectroscopy (FT-IR). That is, in the water vapor barrier layeraccording to such an aspect, the Si—O bond and the Si—N bond can beconfirmed by measuring the absorption of light in the infrared region.In the present specification, FT-IR refers to, for example, thosemeasured by the microscopic ATR method using Spotlight 150, which ismanufactured by PerkinElmer Inc.

In addition, the water vapor barrier layer having an Si—O bond and anSi—N bond can be a layer having relatively high toughness. This meansthat the water vapor barrier layer suitably acts during charging anddischarging of the solid-state battery. When the solid-state battery ischarged and discharged, ions move between the positive and negativeelectrode layers through the solid electrolyte layer, and thereby thesolid-state battery may expand and contract. However, when subjected tosuch a stress of expansion and contraction, the water vapor barrierlayer, having high toughness, is less likely to being cleaved orcracked. Usually, a layer having a high water vapor barrier property maybe densely hard and have a tendency to be easily cleaved or cracked dueto stress or the like, whereas a layer having a relatively soft propertywithout being cleaved or cracked may have a tendency to have a low watervapor barrier property. In this respect, the water vapor barrier layercontaining an Si—O bond and an Si—N bond becomes a layer that is lesslikely to be cleaved or cracked when subjected to stress of expansionand contraction by the solid-state battery, but is excellent in watervapor permeability, increasing in reliability as a solid-state batterypackage.

Preferably, the water vapor barrier layer having Si—O bonds and Si—Nbonds is formed from a liquid raw material. Specifically, it ispreferable to form a water vapor barrier layer having both an Si—O bondand an Si—N bond by applying a liquid raw material to a substrate andsubjecting the substrate to light irradiation. As a result, the watervapor barrier layer can be formed without being subjected to a highertemperature, and the adverse thermal influence on the substrate can besuppressed. In addition, the vacuum vapor deposition method and the likerequire an expensive vapor deposition apparatus, but formation usingsuch a liquid raw material does not require such an expensive apparatus,and also relatively suppress the cost. Furthermore, although a layerformed by a vacuum vapor deposition method or the like may cause warpageof the substrate due to stress acting on the layer, the layer formedfrom a liquid raw material as described above has little orsubstantially no such stress. Therefore, when the water vapor barrierlayer is produced from the liquid raw material, the possibility that thesubstrate warps or the like is reduced or prevented.

In addition, in an aspect of the present invention, a resist layer 400can be disposed between the substrate 200 and the solid-state battery100 (see FIG. 2 and the like). In particular, due to the resist providedon the substrate 200, the resist layer 400 may be provided between thesubstrate 200 and the solid-state battery 100.

The resist layer 400 is particularly provided on the main surface of thesubstrate 200. The resist layer 400 is a layer that at least partlycovers the substrate surface in order to keep away physical processingor chemical reaction. Therefore, the resist layer may be an insulatinglayer including a resin material provided on the main surface of thesubstrate 200. Such a resist layer can also be regarded as correspondingto a heat-resistant coating provided on the main surface of thesubstrate 200. For example, the resist may be used to maintaininsulation at the time of connection between the solid-state battery andthe substrate and to protect a conductor portion such as the substrateelectrode layers. The resist layer 400 provided on the main surface ofthe substrate 200 may be, for example, a solder resist layer.

As an example, the resist layer 400 may be provided on the main surfaceof the substrate 200. In such a case, the water vapor barrier layer 300may be disposed at least on the resist layer 400. The water vaporbarrier layer 300 is disposed so as to be in direct contact with theresist layer 400 such that the water vapor barrier layer 300 and theresist layer 400 are stacked on each other. When the water vapor barrierlayer is provided on the resist layer as described above, water vaporinfiltrating from the external environment via the substrate 200 and theresist layer 400 thereon can be more effectively prevented.

[Method for Manufacturing Solid-State Battery Package]

The objective product according to the present invention can be obtainedthrough a process of preparing a solid-state battery that includes abattery constituent unit including a positive electrode layer, anegative electrode layer, and a solid electrolyte between the electrodesand next packaging the solid-state battery.

The manufacture of the solid-state battery according to the presentinvention can be roughly divided into: manufacturing a solid-statebattery itself (hereinafter, also referred to as an “unpackagedbattery”) corresponding to a stage prior to packaging; preparing asubstrate; and packaging.

<<Method for Manufacturing Unpackaged Battery>>

The unpackaged battery can be manufactured by a printing method such asscreen printing, a green sheet method with a green sheet used, or acombined method thereof. More particularly, the unpackaged batteryitself may be fabricated in accordance with a conventional method formanufacturing a solid-state battery (thus, for raw materials such as thesolid electrolyte, organic binder, solvent, optional additives, positiveelectrode active material, and negative electrode active materialdescribed below, those for use in the manufacture of known solid-statebatteries may be used).

Hereinafter, for better understanding of the present invention, onemanufacturing method will be exemplified and described, but the presentinvention is not limited to this method. In addition, the followingtime-dependent matters such as the order of descriptions are merelyconsidered for convenience of explanation and are not necessarily boundby the matters.

(Formation of Stack Block)

The solid electrolyte, the organic binder, the solvent, and optionaladditives are mixed to prepare a slurry. Then, from the prepared slurry,sheets including the solid electrolyte are formed by firing.

The positive electrode active material, the solid electrolyte, theconductive material, the organic binder, the solvent, and optionaladditives are mixed to prepare a positive electrode paste. Similarly,the negative electrode active material, the solid electrolyte, theconductive material, the organic binder, the solvent, and optionaladditives are mixed to prepare a negative electrode paste.

The positive electrode paste is applied by printing onto the sheet, anda current collecting layer and/or a negative layer are applied byprinting, if necessary. Similarly, the negative electrode paste isapplied by printing onto the sheet, and a current collecting layerand/or a negative layer are applied by printing, if necessary.

The sheet with the positive electrode paste applied by printing and thesheet with the negative electrode paste applied by printing arealternately stacked to obtain a stacked body. Further, the outermostlayer (the uppermost layer and/or the lowermost layer) of the stackedbody may be an electrolyte layer, an insulating layer, or an electrodelayer.

(Formation of Battery Fired Body)

The stacked body is integrated by pressure bonding, and then cut into apredetermined size. The cut stacked body obtained is subjected todegreasing and firing. Thus, a fired stacked body is obtained. Thestacked body may be subjected to degreasing and firing before cutting,and then cut.

(Formation of End-face Electrode)

The end-face electrode on the positive electrode side can be formed byapplying a conductive paste to the positive electrode-exposed sidesurface of the fired stacked body. Similarly, the end-face electrode onthe negative electrode side can be formed by applying a conductive pasteto the negative electrode-exposed side surface of the fired stackedbody. The end-face electrodes on the positive electrode side and thenegative electrode side may be provided so as to extend to a mainsurface of the fired laminate. The component for the end-face electrodecan be selected from at least one selected from silver, gold, platinum,aluminum, copper, tin, and nickel.

Further, the end-face electrodes on the positive electrode side and thenegative electrode side are not limited to being formed after firing thestacked body, and may be formed before the firing and subjected tosimultaneous firing.

Through the steps described above, a desired unpackaged battery(corresponding to the solid-state battery 100 illustrated in FIG. 13A)can be finally obtained.

<<Preparation of Substrate>>

In this step, the substrate is prepared.

Although not particularly limited, in the case of using a resinsubstrate as the substrate, the substrate may be prepared by stackingmultiple layers and then performing heating and pressurizing treatmentsfor the layers. For example, a substrate precursor is formed using aresin sheet made by impregnating a fiber cloth as a substrate with aresin raw material. After the formation of the substrate precursor, thesubstrate precursor is subjected to heating and pressurization with apress machine. In contrast, in the case of using a ceramic substrate asthe substrate, for the preparation thereof, for example, multiple greensheets can be subjected to thermal compression bonding to form a greensheet laminate, and the green sheet laminate can be subjected to firing,thereby providing a ceramic substrate. The ceramic substrate can beprepared, for example, in accordance with the preparation of an LTCCsubstrate. The ceramic substrate may have vias and/or lands. In such acase, for example, holes may be formed for the green sheet with a punchpress, a carbon dioxide gas laser, or the like, and filled with aconductive paste material, or a conductive part precursor such as viasand lands may be formed through performing a printing method or thelike. Further, lands and the like can also be formed after firing thegreen sheet laminate.

Thereafter, the substrate electrode layer 210 is formed on the mainsurface 230 of the substrate 200 for electrical connection (see FIG.13B). The substrate electrode layer may be appropriately patterned.Specifically, the substrate electrode layer 210 is formed on the surfaceof the substrate, so that, with respect to a case where one side surfaceof the substrate electrode layer and an end face of the end-faceelectrode on the same electrode side of the subsequently disposedsolid-state battery are substantially on an identical line in asectional view, the distance between one side surface and another sidesurface of the substrate electrode layer is equal to or more than aminimum distance between the end face of the end-face electrode on thesame electrode side and a side surface of the solid-state batteryelectrode layer on an opposite electrode side that is separately opposedto the end face.

After the substrate electrode layer 210 is formed, a resist layer 400made of, for example, solder resist may be formed on the main surface230 of the substrate 200 excluding the substrate electrode layer (seeFIG. 13C). The step of forming the resist layer 400 may be omitted. Bycarrying out the steps as described above, a desired substrate can befinally obtained.

<<Packaging>>

Next, packaging is performed using the battery and substrate obtained asmentioned above.

First, the unpackaged battery 100 is placed on the substrate 200 (seeFIG. 13D). More particularly, the “unpackaged solid-state battery” isplaced on the substrate (hereinafter, the battery used for packaging isalso simply referred to as a “solid-state battery”).

Specifically, the solid-state battery is disposed on the substrate suchthat the substrate electrode layer and the end-face electrode of thesolid-state battery are electrically connected to each other. Forexample, the solid-state battery is disposed while the end face of theend-face electrode of the solid-state battery placed on the substrateand one side surface of the substrate electrode layer are adjusted to besubstantially on an identical line. Note that the end face of theend-face electrode of the solid-state battery and one side surface ofthe substrate electrode layer do not necessarily have to besubstantially an identical line, and the one side surface of thesubstrate electrode layer may be disposed more outward from the end faceof the end-face electrode of the solid-state battery in a sectionalview. At this time, for example, a conductive paste (for example, Agconductive paste) may be provided on the substrate electrode layer ofthe substrate before the solid-state battery is disposed, therebyelectrically connecting the conductive portion of the support substrateand the end-face electrode of the solid-state battery to each other.More particularly, a precursor 600′ of the bonding member that plays apart in electrical connection between the solid-state battery 100 andthe substrate 200 may be provided in advance. Such a precursor 600′ ofthe bonding member can be provided by printing with a conductive pastethat requires no cleaning such as flux after being formed, such as anano-paste, an alloy-based paste, and a brazing material, in addition toan Ag conductive paste. The solid-state battery 100 is disposed on thesubstrate so that the end-face electrode of the solid-state battery andthe precursor 600′ of the bonding member are in contact with each other,and then subjected to a heat treatment, whereby the bonding member 600contributing to electrical connection between the solid-state battery100 and the substrate 200 is formed from the precursor 600′.

Next, the covering material 150 is formed. As the covering material, acovering insulating layer 160 and a covering inorganic layer 170 may beprovided (see FIG. 13E).

First, the covering insulating layer 160 is formed so as to cover thesolid-state battery 100 on the substrate 200. Hence, a raw material forthe covering insulating layer is provided such that the solid-statebattery on the substrate is totally covered. When the coveringinsulating layer is made of a resin material, a resin precursor isprovided on the substrate and subjected to curing or the like to moldthe covering insulating layer. According to a preferred aspect, thecovering insulating layer may be molded by pressurization with a mold.By way of example only, a covering insulating layer for sealing thesolid-state battery on the substrate may be molded through compressionmolding. In a case of a resin material generally for use in molding, theform of the raw material for the covering insulating layer may begranular, and the type thereof may be thermoplastic. It is to be notedthat such molding is not limited to die molding, and may be performedthrough polishing processing, laser processing, and/or chemicaltreatment.

After the covering insulating layer 160 is formed, the coveringinorganic layer 170 is formed. Specifically, the covering inorganiclayer 170 is formed on the “covering precursor in which each solid-statebattery 100 is covered with the covering insulation layer 160 on thesubstrate 200”. For example, dry plating may be performed to form a dryplating film as the covering inorganic layer. More specifically, dryplating is performed to form the covering inorganic layer on the exposedsurface other than the bottom surface of the covering precursor (thatis, other than the bottom surface of the support substrate).

Through the steps described above, it is possible to obtain a packagedarticle in which the solid-state battery on the substrate is totallycovered with the covering insulating layer and the covering inorganiclayer. More particularly, the “solid-state battery package” according tothe present invention can be finally obtained.

In the above description, an aspect in which the covering material 150covers the solid-state battery 100 has been mentioned, but the presentinvention may have an aspect in which the solid-state battery 100 islargely covered with the covering material 150. For example, thecovering inorganic layer 170 provided on the covering insulating layer160 that covers the solid-state battery 100 on the substrate 200 mayextend to the lower main surface of the substrate 200 (see FIG. 2 ).That is, as the covering material 150, the covering inorganic layer 170on the covering insulating layer 160 may extend to the side surface ofthe substrate 200, and beyond the side of the substrate 200, extend tothe lower main surface (particularly, the peripheral edge portionthereof) of the substrate 200. In the case of such a form, a solid-statebattery package may be provided in which moisture transmission (moisturetransmission from the outside to the solid-state battery stacked body)is more suitably prevented. As illustrated in FIG. 11 , the coveringinorganic layer 170 can also be provided as a multilayer structurecomposed of at least two layers. In FIG. 11 , the covering inorganiclayer 170 having a two-layer structure of 170A and 170B is illustrated.Such a multilayer structure is not particularly limited to betweendifferent types of materials, and may be between the same type ofmaterials. When the covering inorganic layer having such a multilayerstructure is provided, it is easy to more suitably configure the watervapor barrier for the solid-state battery.

Preferably, the substrate may have a water vapor barrier layer havingbeen formed thereon. More particularly, the water vapor barrier may beformed for the substrate, prior to the packaging, where the substrateand the solid-state battery are combined.

The water vapor barrier layer is not particularly limited as long as adesired barrier layer can be formed. For example, in the case of the“water vapor barrier layer having an Si—O bond and an Si—N bond”, thewater vapor barrier layer is preferably formed through application of aliquid raw material and ultraviolet irradiation. More particularly, thewater vapor barrier layer is formed under a relatively low temperaturecondition (for example, a temperature condition on the order of 100° C.)without using any vapor-phase deposition method such as CVD or PVD.

Specifically, a raw material containing, for example, silazane isprepared as the liquid raw material, and the liquid raw material isapplied to the substrate by spin coating, spray coating, or the like,and dried to form a barrier precursor. Then, the barrier precursor canbe subjected to UV irradiation in an environmental atmosphere containingnitrogen, thereby providing the “water vapor barrier layer having anSi—O bond and an Si—N bond”.

In order that the water vapor barrier layer is not present at thebonding site of the conductive portion of the substrate and the end-faceelectrode of the solid-state battery, it is preferable to locally removethe barrier layer at the site. Alternatively, a mask may be used suchthat the water vapor barrier layer is not formed at the bonding site.More particularly, the water vapor barrier layer may be totally formedwith a mask applied to the region for the bonding site, and then themask may be removed.

When a resist layer is provided on the main surface of the substrate, awater vapor barrier layer may be formed on the resist layer 400. At thistime, as described above, it is preferable to form the water vaporbarrier layer so as to exclude the bonding region with the solid-statebattery 100. That is, it is preferable to prepare the substrate 200 onwhich the resist layer 400 and the water vapor barrier layer 300 areformed so that the substrate electrode layer 210 of the substrate isexposed.

Although the aspects of the present invention have been described above,only typical examples have been illustrated. Those skilled in the artwill easily understand that the present invention is not limitedthereto, and various aspects are conceivable without changing the gistof the present invention.

For example, in the above description, an aspect in which the conductiveportion of the substrate and the end-face electrode of the solid-statebattery are electrically connected to each other using a conductivepaste has been mentioned, and the conductive paste corresponding to theprovided bonding member 600 may finally have a form as shown in FIG. 12. When the solid-state battery 100 and the substrate 200 areelectrically connected via the conductive paste, a pressing force isapplied from the solid-state battery 100 to the conductive paste, sothat the end-face electrode 140 of the solid-state battery 100 tends toslightly bite into the conductive paste. That is, the conductive pasteis likely to have a form in which it is pressed by the end-faceelectrode 140 and slightly swells outside thereof (the “M” portion inFIG. 12 ). When the solid-state battery 100 and the substrate 200 areelectrically bonded to each other with the conductive paste interposedtherebetween, a part 600A of the conductive paste may flow so as tostraddle the resist layer 400 due to the pressing. This is related tothe fact that the resist layer 400 acts as a “dam” on the conductivepaste.

More specifically, in the opening portion of the resist layer 400 wherethe conductive portion of the substrate (in particular, the main surfaceelectrode layer 210 of the substrate) is exposed, the edge portionforming the opening acts so as to partly prevent the conductive pastemoving. Therefore, while the part 600A of the conductive paste onceprovided into the opening portion flows onto the resist layer 400 alongwith the pressing, a large part 600B of the conductive paste can remainin the opening portion of the resist layer 400. That is, preferably, theresist layer (for example, a solder resist layer) acts as a dam tosuppress the bleeding of the conductive paste. When the bleeding of theconductive paste is suppressed, the bonding area between the coveringinsulating layer 160 (particularly, the covering insulating layer 160provided between the solid-state battery 100 and the substrate 200) andthe resist layer 400 is more easily secured. As a result, the fixingforce between the covering insulating layer 160 and the substrate 200can be further stabilized. Although the conductive paste is expressed onthe premise of manufacturing, the conductive paste corresponds to thebonding member 600 in the manufactured solid-state battery. Therefore,in the solid-state battery package 1000 according to an aspect of thepresent disclosure, as illustrated in FIG. 12 , the bonding member 600can be disposed so as to straddle the upper main surface electrode layer210 of the substrate and the resist layer 400. That is, the part 600A ofthe bonding member 600 can be disposed inward from the resist layer 400.Specifically, the part 600A of the bonding member 600 can be disposedmore inward from the portion of the resist layer 400 in contact with theupper main surface electrode layer 210.

Although the present invention relates to a solid-state battery package,the package may be provided as an electronic device mounted on anexternal board separate from the substrate. That is, while the substrateof the solid-state battery package can be a terminal substrate for theexternal terminal of the solid-state battery, the solid-state batterypackage may be surface-mounted on an external board (that is, thesecondary substrate) such as a printed wiring board via the terminalsubstrate, and the solid-state battery package may be provided as suchan electronic device.

The solid-state battery package according to the present invention canbe used in various fields where battery use or power storage can beassumed. By way of example only, the solid-state battery packageaccording to the present invention can be used in the fields ofelectricity, information, and communication in which mobile devices andthe like are used (such as the field of electric/electronic devices andthe field of mobile devices including small electronic devices such asmobile phones, smartphones, notebook computers and digital cameras,activity trackers, arm computers, electronic paper, RFID tags, card-typeelectronic money, and smartwatches), home and small industrialapplications (such as the fields of power tools, golf carts, and home,nursing, and industrial robots), large industrial applications (such asthe fields of forklifts, elevators, and harbor cranes), the field oftransportation systems (such as the fields of hybrid vehicles, electricvehicles, buses, trains, power-assisted bicycles, and electrictwo-wheeled vehicles), power system applications (such as the fields ofvarious types of power generation, road conditioners, smart grids, andhome energy storage systems), medical applications (field of medicalequipment such as earphone hearing aids), pharmaceutical applications(fields such as dosage management systems), IoT fields, space and deepsea applications (such as the fields of space probes and submersibles),and the like.

DESCRIPTION OF REFERENCE SYMBOLS

-   -   100: Solid-state battery    -   100A: Main surface of solid-state battery    -   100B: Side surface of solid-state battery    -   100X: Battery element    -   100X1: Central region of interface region and battery element    -   110: Positive electrode layer    -   115: Solid-state battery electrode layer    -   115 a: Side surface of solid-state battery electrode layer    -   120: Negative electrode layer    -   130: Solid electrolyte or solid electrolyte layer    -   140: End-face electrode    -   140A: End-face electrode on positive electrode side    -   140B: End-face electrode on negative electrode side    -   141: End face of end-face electrode    -   150: Covering material    -   160: Covering insulating layer    -   170: Covering inorganic layer    -   180: Interface region of solid-state battery electrode layer and        end-face electrode    -   200: Substrate    -   210: Substrate electrode layer (substrate upper side)    -   210A: Positive-electrode-side substrate electrode layer    -   210B: Negative-electrode-side substrate electrode layer    -   211: One side surface of substrate electrode layer    -   212: Another side surface of substrate electrode layer    -   220: Substrate electrode layer on mounting side (substrate lower        side)    -   220A: Positive-electrode-side substrate electrode layer on        mounting side    -   220B: Negative-electrode-side substrate electrode layer on        mounting side    -   230: One main surface of substrate    -   240: Another main surface of substrate    -   250: Side surface of substrate    -   300: Water vapor barrier layer    -   400: Resist layer    -   600: Bonding member    -   600A: Part of bonding member    -   600B: Large part of bonding member    -   600′: Bonding member precursor    -   1000: Solid-state battery package    -   L1: Distance between one side surface and another side surface        of substrate electrode layer    -   L2: Minimum distance between end face of end-face electrode on        the same electrode side and side surface of solid-state battery        electrode layer on opposite electrode side    -   L3: Maximum distance between end face of end-face electrode on        the same electrode side and side surface of solid-state battery        electrode layer on opposite electrode side    -   L4: Distance between one side surface of substrate electrode        layer and end face of end-face electrode

1. A solid-state battery package comprising: a substrate; and asolid-state battery on the substrate, wherein the solid-state batteryhas: a battery element having a positive electrode layer, a negativeelectrode layer, and a solid electrolyte interposed between the positiveelectrode layer and the negative electrode layer; and an end-faceelectrode on an end face of the battery element and connected to one ofthe positive electrode layer or the negative electrode layer, whereinthe substrate has, on a main surface thereof on a side opposite to thesolid-state battery, a substrate electrode layer, and at least a firstside surface of the substrate electrode layer and a first end face ofthe end-face electrode are substantially on an identical line in asectional view of the solid-state battery package, a distance betweenthe first side surface and a second side surface of the substrateelectrode layer opposite to the first side surface is equal to or morethan a minimum distance between the first end face of the end-faceelectrode and an end surface of the one of the positive electrode layeror the negative electrode layer that the end-face electrode is notconnected.
 2. The solid-state battery package according to claim 1,wherein the second side surface of the substrate electrode layer and theend surface of the one of the positive electrode layer or the negativeelectrode layer that the end-face electrode is not connected aresubstantially on an identical line in the sectional view.
 3. Thesolid-state battery package according to claim 1, wherein the secondside surface of the substrate electrode layer is positioned more inwardfrom an interface region of the one of the positive electrode layer orthe negative electrode layer that the end-face electrode is notconnected and the end-face electrode in the sectional view.
 4. Thesolid-state battery package according to claim 1, wherein the substrateelectrode layer is a metal layer.
 5. The solid-state battery packageaccording to claim 1, wherein the substrate electrode layer is astress-receiving layer.
 6. The solid-state battery package according toclaim 1, wherein the second side surface of the substrate electrodelayer is positioned more inward from the end surface of the one of thepositive electrode layer or the negative electrode layer that theend-face electrode is not connected in the sectional view.
 7. Thesolid-state battery package according to claim 1, wherein the substrateelectrode layer extends to a position where the substrate electrodelayer is opposed to the one of the positive electrode layer or thenegative electrode layer that the end-face electrode is not connected inthe sectional view.
 8. The solid-state battery package according toclaim 1, wherein a distance between the first side surface and thesecond side surface of the substrate electrode layer is 1.5 times ormore of the minimum distance in the sectional view.
 9. The solid-statebattery package according to claim 1, wherein the distance between thefirst side surface and the second side surface of the substrateelectrode layer is 2.0 times or more of the minimum distance in thesectional view.
 10. The solid-state battery package according to claim1, wherein the substrate further has, on the main surface of thesubstrate, a dummy substrate electrode layer that is separately opposedto the substrate electrode layer and is not electrically connected tothe solid-state battery.
 11. The solid-state battery package accordingto claim 1, further comprising a water vapor barrier layer between thesubstrate and the solid-state battery.
 12. The solid-state batterypackage according to claim 11, wherein the water vapor barrier layerextends along an extending direction of the main surface of thesubstrate.
 13. The solid-state battery package according to claim 11,further comprising a covering insulating layer covering a main surfaceand a side surface of the solid-state battery on the substrate, whereinthe water vapor barrier layer extends to an outer surface of thecovering insulating layer which covers the side surface of thesolid-state battery.
 14. The solid-state battery package according toclaim 11, wherein the water vapor barrier layer is an insulating layerhaving an electrical insulation property.
 15. The solid-state batterypackage according to claim 11, wherein the water vapor barrier layer hasboth an Si—O bond and an Si—N bond.
 16. The solid-state battery packageaccording to claim 11, further comprising a resist layer between thesubstrate and the water vapor barrier layer.
 17. The solid-state batterypackage according to claim 1, wherein the substrate is a resinsubstrate.
 18. A solid-state battery package comprising: a substrate;and a solid-state battery on the substrate, wherein the solid-statebattery has: a battery element having a positive electrode layer, anegative electrode layer, and a solid electrolyte interposed between thepositive electrode layer and the negative electrode layer; and anend-face electrode on an end face of the battery element and connectedto one of the positive electrode layer or the negative electrode layer,wherein the substrate has, on a main surface thereof on a side oppositeto the solid-state battery, a substrate electrode layer, and at least afirst side surface of the substrate electrode layer is positioned moreoutward from an end face of the end-face electrode and positioned moreinward from an end of the main surface of the substrate in a sectionalview of the solid-state battery package, and a distance between thefirst side surface and a second side surface of the substrate electrodelayer opposite to the first side surface is equal to or more than aminimum distance between the first end face of the end-face electrodeand an end surface of the one of the positive electrode layer or thenegative electrode layer that the end-face electrode is not connected.19. The solid-state battery package according to claim 18, furthercomprising a water vapor barrier layer between the substrate and thesolid-state battery.
 20. The solid-state battery package according toclaim 19, further comprising a resist layer between the substrate andthe water vapor barrier layer.